To study the pollution status and ecological safety of organophosphate insecticides （OPs） along the inflow routes to Taihu Lake Basin， water， suspended particulates （SPM） and sediment samples were collected from the watershed during the abundant and dry seasons， and the GC method was used to detect the types and contents of OPs， analyze the seasonal distribution patterns， partition coefficients， and potential sources of contamination， and then assess the ecological risks. Phoxim （PHO）， dichlorvos （DDVP）， dimethoate （DMT） and fenitrothion （MEP） were detected in water， SPM and sediment samples. In the water samples， the concentrations of PHO， DMT and DDVP were relatively high and they accounted for a larger proportion， while MEP was relatively less. The K_d1 and K_d2 of Σ₄OPs were 0.44~1.32 L·g^-1 and 2.97~6.88 L·g^-1 respectively during the abundant water period， and 0.34~1.40 L·g^-1 and 2.85~7.43 L·g^-1 respectively during the depleted water period， which indicated that the distributions of the OPs were relatively stable in the water samples， SPM samples and the sediments. To sum up， the water along the the Taihu Lake basin has been polluted by organophosphorus pesticides. The discharge of industrial and agricultural wastewater may be the main source of OPs along the Taihu Lake basin， and the two OPs pollutants DMT and MEP have potential ecological risks to the main rivers along the Tongji River in Zhenjiang City.

To investigate the essential oil content and compositional characteristics of different peppermint varieties， 25 collected peppermint varieties resources were analyzed. The experiment utilized steam distillation to extraet peppermint essenitial oil， and analyzed components using gas chromatography-mass spectrometry （GC-MS）. The study compared the content and group characteristics of bioactive chemical constituents across these varieties. Results revealed that the oil content of 24 peppermint varieties ranged from 0.03% to 1.52%， with Gold Mint showing the highest content （1.52%）. A total of 53 volatile components were identified in 22 essential oils， with alcohols and terpenes universally present. Menthol was the predominant alcohol， reaching 76.45% in Gold Mint， while esters such as linalyl acetate （48.66% in Japanese Mint） were secondary major components. Terpene compounds， including β?-caryophyllene， germacrene D， limonene， and 1，8-cineole， were detected in 21 varieties. Variations in essential oil composition were observed among peppermint resources， yet these differences showed no correlation with genetic relatedness. Gold Mint emerged as the variety with both high oil yield and superior quality. This study clarifies the biological traits and essential oil profiles of peppermint， providing a scientific foundation for its utilization in essential oil applications.

This study aimed to investigate the mechanism by which miR-93 promotes traumatic brain injury （TBI） repair through regulating macrophage M2 polarization and neurovascular tissue regeneration via the PI3K/AKT signaling pathway.Female C57BL/6 mice were randomly assigned to four groups： sham-operated （Sham）， TBI model （TBI）， TBI + miR-93 inhibitor （TBI+inhibitor）， and TBI + miR-93 agonist （TBI+agonist）. Relative mRNA expression levels of M1 macrophage marker CD80 and M2 macrophage marker CD206 were assessed by quantitative real-time PCR （qPCR）. Concentrations of inflammatory cytokines TNF-α， IL-12， TGF-β， and IL-13 were measured using enzyme-linked immunosorbent assay （ELISA）. Immunofluorescence staining for vascular endothelial growth factor （VEGF） was performed to evaluate angiogenesis post-TBI. Western blotting was used to determine the relative protein expression levels of phosphorylated PI3K （p-PI3K） and phosphorylated AKT （p-AKT）.Compared to the TBI group， the TBI+agonist group exhibited enhanced M2 macrophage polarization， reduced expression of pro-inflammatory cytokines TNF-α and IL-12， and increased expression of anti-inflammatory cytokines TGF-β and IL-13. Furthermore， this group showed a lower modified Neurological Severity Score （mNSS）， indicative of improved neurological function， enhanced VEGF expression reflecting active angiogenesis， and elevated levels of p-PI3K and p-AKT proteins.These results suggested that miR-93 expression is compensatorily upregulated following TBI. miR-93 promotes neurovascular repair after injury by modulating macrophage polarization towards the M2 phenotype， likely via activation of the PI3K/AKT signaling pathway.

To explore the effects of drought stress on the physiological characteristics and drought resistance adaptation mechanism of the seedlings of the medicinal plant Glycyrrhiza uralensis， one-year-old licorice seedlings were used as materials. Using potted plants with controlled water supply to simulate drought stress， we setted up normal water supply control （CK）， light stress （LS）， moderate stress （MS） and severe stress （SS） gradients， and measured key physiological parameters such as the antioxidant system and osmotic regulatory substances. The results showed that with the intensification of drought stress， the contents of malondialdehyde （MDA） and H₂O₂ in the leaves and roots of licorice generally showed an increasing trend， while the content of {\mathrm{O}}_{\mathrm{2}}^{-} in the roots of licorice in the MS group and the SS group was lower than that of CK. The total antioxidant capacity and peroxidase （POD） of roots both showed a trend of first increasing and then decreasing， while the POD and catalase （CAT） activities of leaves first decreased and then increased， and the superoxide dismutase （SOD） activities of leaves and roots both showed a trend of first increasing and then decreasing. After drought stress， the ascorbic acid （ASA） content， glutathione peroxidase （GPX） and GSSG activities in licorice leaves and roots were all higher than those in CK. In conclusion， studies have shown that licorice seedlings can resist mild to moderate drought stress by enhancing the antioxidant enzyme system in leaves and roots and accumulating osmotic regulatory substances. Severe drought exceeds their physiological tolerance threshold， and the drought resistance of leaves is stronger than that of roots. This result provides a physiological basis for water management and drought-resistant germplasm screening of artificial cultivation of licorice in arid areas.

To evaluate the genetic polymorphism of 38 Y-chromosomal short tandem repeat （Y-STR） loci in the Han population of Hohhot， Inner Mongolia Autonomous Region， and to explore their forensic application value and genetic relationships with other domestic populations， a multiplex amplification system comprising 38 Y-chromosomal genetic markers was used to amplify samples from 272 randomly selected unrelated Han male individuals in Hohhot City. Allele frequencies and forensic genetic parameters for the 38 Y-STR loci were calculated. Based on haplotype data from domestic populations included in the Y-chromosomal short tandem repeat haplotype reference database （YHRD）， pairwise genetic distances （Rst） between populations were computed， followed by multidimensional scaling （MDS） analysis. A total of 333 alleles were detected across the 38 Y-STR loci， with gene diversity （GD） values ranging from 0.043 4 to 0.967 5. In total， 269 haplotypes were observed， with three haplotypes occurring twice. Haplotype diversity （HD） and discrimination power （DC） were 0.999 9 and 0.989 0， respectively. Population comparison results revealed that the Hohhot Han population exhibited smaller genetic distances （indicating closer genetic relationships） with groups of the same ethnicity or geographically proximate populations， such as the Shaanxi Han population， and conversely， larger genetic distances （indicating more distant relationships） with other groups. The selected multiplex detection system containing 38 Y-STR loci demonstrated high genetic polymorphism， making it suitable for forensic analysis and population genetic studies of the Han population in Hohhot.

In order to investigate the immunotoxicity and mechanism of action of dinotefuran （DIN） on early developmental stages of zebrafish， zebrafish larvae were exposed to different concentrations of DIN （2， 200 and 2 000 μg?L^-1） for 5 days to investigate changes in oxidative stress， immune cells， immune-related parameters and immune-related pathways. The results demonstrated that DIN significantly reduced the number of neutrophil， macrophage and thymic T cells （P<0.01）， decreased the levels of immune factors （LYS， IgM and C3） （P<0.01）， and increased the levels of inflammatory factors （IL-1β， IL-6， and TNF-α） （P<0.01）. DIN dose-dependently increased the levels of reactive oxygen species （ROS） in juvenile fish （P<0.01） and inhibited antioxidant enzyme activities （CAT， SOD and GSH-Px） （P<0.01）. Concurrently， DIN exposure modulated the transcript levels of pivotal genes within the TLR4/NF-κB， JAK-STAT and Nrf2-Keap1 signalling pathways. The study demonstrated that DIN exposure could induce immunotoxicity in zebrafish larvae and that the TLR4/NF-κB， JAK-STAT and Nrf2-Keap1 pathways play a significant role in this process.

To enhance the extreme high-temperature adaptability of Esox lucius for aquaculture expansion to southern warm regions and identify genetic loci associated with thermal tolerance， we integrated genome-wide association study （GWAS） and transcriptome analysis. Using reduced-representation genome sequencing data from heat-sensitive and heat-tolerant populations， GWAS analysis with an MLM model identified 471 SNPs significantly associated with thermal tolerance traits. Concurrently， transcriptome sequencing of juvenile brain tissues exposed to varying heat stress durations revealed differential gene expression patterns. Functional enrichment analyses demonstrated significant enrichment of differentially expressed genes （DEGs） in endoplasmic reticulum stress and immune-related pathways. GSEA analysis indicated activation of innate immune responses at 84 h of heat stress， with specific induction of NAD（+） ADP-ribosyltransferase activity-related genes. Protein-protein interaction （PPI） network analysis identified parp14， parp9， stat1， and stat3 as core regulators of innate immune responses. Notably， two GWAS-derived SNPs located in exon 3 of the parp14 gene—rsc.646T>C （missense mutation） and rsc.777G>A （synonymous mutation）—exhibited complete linkage disequilibrium and were significantly correlated with thermal tolerance traits. Sanger sequencing validation in heat-stressed and reference populations confirmed these associations. Our findings reveal candidate genes and functional SNP markers for high-temperature tolerance in E. lucius， providing insights into its genetic mechanisms and supporting marker-assisted breeding strategies.

The genetic transformation of cotton is constrained by multiple limiting factors， including genotype restrictions and protracted transformation cycles， resulting in low transformation efficiency. In this study， embryonic tips of upland cotton TM-1 were selected as recipient material for Agrobacterium-mediated transformation using a GhTCP4 gene editing vector. We systematically investigated the effects of different concentrations of exogenous hormones 6-benzylaminopwrine （6-BA） and naphthalene acetic acid （NAA） in plant regeneration media， ultimately determining that hormone-free medium yielded optimal recovery. Furthermore， three auxiliary treatments， ultrasonication， vacuum infiltration， and their combination， were evaluated for their impacts on transformation efficiency. The results demonstrated that 15 minute ultrasonic treatment at 40 kHz frequency with 300 W rated power achieved the highest transformation efficiency of 26.86%. This study provided methodological insights for establishing an efficient cotton embryonic tip transformation system and offered a foundation for future functional gene research and genetic transformation applications in cotton.

Crop cultivation is a critical component of the food supply chain， and establishing appropriate legal oversight and risk prevention/control systems for this stage is essential to advancing the industrialization of biological breeding crops. Through field surveys of growers， logistic regression， and correlation analysis， this study identified significant correlations between growers' support for biological breeding industrialization and their basic characteristics， including geographic location， cultivated land area， educational attainment， annual household income， internet access， and attitudes toward adopting new crop varieties. However， growers demonstrated limited awareness of biological breeding industrialization and inadequate risk management capabilities. By evaluating growers' acceptance levels and the operational efficiency of biological breeding practices， this research pinpointed key risks in four areas： economic viability， field management， post-harvest storage， and public perception. Finally， risk management strategies were proposed， categorized by responsible stakeholders and prioritized for risk mitigation and prevention.

To investigate the protective mechanism of echinacoside （ECH） in interleukin-1β （IL-1β）-induced chondrocyte iron death. Wistar mammary rat chondrocytes were extracted， and the experiment was divided into 5 groups： control group， IL-1β group， ECH+IL-1β group， ECH+IL-1β+Brusatol （Nrf2 inhibitor） group and ECH+IL-1β+ZnPP （HO-1 inhibitor） group. Quantitative PCR （qPCR） and Western Blot were used to detect mRNA and protein expression nuclear factor E2-related factor 2 （Nrf2）， heme oxygenase-1 （HO-1）， esteroyl coenzyme A synthase long-chain family member 4 （ACSL4） and glutathione peroxidase 4 （GPX4）， respectively. The results showed that the mRNA and protein expression of Nrf2， HO-1 and GPX4 were significantly reduced in the IL-1β group， and the mRNA and protein expression of ACSL4 were significantly enhanced compared with the control group. The mRNA and protein expression of cartilage Nrf2， HO-1 and GPX4 were significantly decreased and that of ACSL4 was significantly enhanced by the addition of the Nrf2 inhibitor Brusatol or the HO-1 inhibitor ZnPP in the ECH group. The results of Fe²⁺ Assay Kit showed that the chondrocyte Fe²⁺ content was significantly higher in the IL-1β group compared to the control group. The chondrocyte Fe²⁺ content was significantly lower in the ECH group （ECH+IL-1β） compared to the IL-1β group， while it was significantly higher in the ECH group after the addition of the Nrf2 inhibitor Brusatol or the HO-1 inhibitor ZnPP. The results suggest that echinoside can significantly improve IL-1β-induced chondrocyte iron death through Nrf2/HO-1 pathway.

With the expanding variety and quantity of genetically modified （GM） plants and their derived products， requirements for nucleic acid detection precision have become increasingly stringent. This study utilized the Web of Science Core Collection database， employing bibliometric methods to comprehensively analyze research trends， primary directions， global research capacity distribution， and China’s scientific standing in GM nucleic acid detection technology. The analysis results showed that as of early 2023， the total number of SCI related to nucleic acid testing technology has reached 2 550， and China ranks first in the global publication volume in this field. More than 90 countries/regions and approximately 2 400 institutions worldwide have participated in the research of GM nucleic acid testing technology. Among the top 20 institutions in terms of publication volume， 7 of them are from China. Among the 30 high-quality journal articles related to GM nucleic acid detection technology， 14 are from China， indicating that relevant research in China has shown a trend of high-quality development. At the same time， this article summarized the current status of different GM nucleic acid testing technologies from multiple dimensions such as paper publication trends， publication volume， and publishing institutions， and analyzed the differences in research trends of the above technologies， aiming to ensure the efficient utilization of scientific research resources and provide data support for regulatory agencies’ strategic decision-making and research directions.

To investigate the relationship between morphological indicators during the germination stage and drought resistance in upland cotton （Gossypium hirsutum L.）， and to identify elite germplasm resources with superior drought tolerance， this study applied polyethylene glycol-6000 （PEG-6000） to simulate drought stress through hypertonic solution， with distilled water as the control. A systematic drought resistance evaluation was performed on 34 cotton varieties （lines） from the Shihezi Reclamation Area. The results indicated that three evaluation methods （the Petri dish filter paper germination method for drought resistance assessment， the germination box sand culture method for drought resistance assessment， and the beaker dual-concentration filter paper method for drought resistance assessment） could effectively identify the drought resistance of cotton during the germination stage. Through comprehensive assessment using membership function analysis， the relative germination vigor， relative germination rate， and relative germination index emerged as key indicators for rapid evaluation， with 44.1% （15 varieties） exhibiting strong drought tolerance. According to the industry standard for germination-stage drought resistance， 32.4% （11 varieties） showed extreme drought tolerance. Using the dual-concentration PEG-6000 method， 11.8% （4 varieties） achieved Level 1 drought resistance classification. All three methods consistently identified four varieties—Xinluzao 79， Xinluzao 84， H16， and Xinzaomian 107—as having exceptional drought resistance. Considering methodological universality and operational simplicity， the dual-concentration PEG-6000 evaluation method is recommended as the preferred approach for drought resistance assessment in upland cotton.

This study introduced the AcGox gene from Aspergillus chevalieri into a Aspergillus niger strain via protoplast transformation technology， yielding the recombinant AcGox protein. Results indicated that recombinant AcGox exhibits optimal activity at pH 6.0 and 32 ℃， demonstrating excellent acid tolerance and good thermal stability. However， the specific activity of AcGox was only 70.81 U·mg^-1，to be a critical bottleneck limiting its application. To address this issue， this study further overexpressed genes encoding riboflavin kinase and FAD synthase in the AcGox-5 strain. RT-qPCR validation confirmed significantly elevated gene transcription levels. Ultimately， the specific activity of glucose oxidase produced by AcGox/FAD/FMN-3 strain increased to 111.55 U·mg^-1，with a 57.5% improvement. This study confirmed that cofactor FAD supply levels are a critical factor limiting the catalytic efficiency of recombinant AcGox. It provides direct experimental evidence for the "cofactor engineering" strategy in enzyme engineering and offers a scalable host modification approach for industrial glucose oxidase production， advancing the application of glucose oxidase.

Megakaryocytes are a type of cell primarily present in adult bone marrow， with the main function of producing platelets. In addition， adult bone marrow megakaryocytes also play a role in maintaining the homeostasis of hematopoietic stem cells （HSCs）. Recent studies have revealed that megakaryocytes also exist in the aorta-gonad-mesonephros （AGM） region and are involved in regulating the generation and maturation of hematopoietic stem cell precursors （pre-HSCs）. The AGM region is the earliest site for HSC production， while the bone marrow is the main site for HSC colonization and hematopoiesis in adulthood. However， it remains unclear whether megakaryocytes regulate HSC development and function through distinct molecular mechanisms at these two sites. Based on recently reported single-cell transcriptome data of megakaryocytes from the AGM region in mouse embryos and from adult bone marrow， we performed a comparative analysis of their overall molecular characteristics and the molecular features associated with regulating HSC biological processes. The results showed significant differences in molecular characteristics between AGM region megakaryocytes and adult bone marrow megakaryocytes in mice. Specifically， AGM region megakaryocytes highly expressed molecular features related to cell proliferation， circulatory system development， stem cell development， and differentiation； in contrast， adult bone marrow megakaryocytes highly expressed molecular features associated with immune response， response to external stimuli， hemostasis and coagulation， and cell communication. Furthermore， AGM region megakaryocytes and adult bone marrow megakaryocytes highly expressed different HSC regulation-related molecules. These findings suggested that megakaryocytes in the AGM region and adult bone marrow may regulate HSC development and function through distinct functional molecules， providing a theoretical basis for investigating the functional differences between embryonic and adult megakaryocytes and their underlying molecular mechanisms.

The malignant progression of colorectal cancer （CRC） is closely associated with abnormal activation of critical oncogenes. Analysis of the cancer genome atlas （TCGA） omics data revealed that DBNDD1 is significantly upregulated in CRC tissues， with its overexpression demonstrating a significant correlation with shorter overall patient survival. This study aimed to investigate the expression characteristics， biological functions， and clinical significance of DBNDD1 in CRC. The research integrated omics analysis with experimental validation， evaluating the prognostic relevance of DBNDD1 expression through the TCGA database， assessing migration， invasion capabilities （Transwell assay， wound healing assay）， and apoptosis levels （flow cytometry） in HCT116 cells following DBNDD1 knockdown using siRNA， and monitoring tumor growth and apoptosis changes （Ki-67 immunohistochemistry， TUNEL assay） in nude mouse xenograft models. Gene set enrichment analysis （GSEA） was further employed to explore associated signaling pathways and immune microenvironment regulatory mechanisms. The experimental results demonstrated that DBNDD1 knockdown suppressed migration and invasion capabilities of HCT116 cells while promoting apoptosis. Mechanistic analysis revealed significant enrichment of NF-κB and TNF signaling pathways in DBNDD1-overexpressing samples， along with close associations with immunosuppressive microenvironment features， including increased infiltration of M2 macrophages and regulatory T cells. These findings provide novel research directions for the development of clinical molecular biomarkers and targeted therapeutic strategies in colorectal cancer.

To investigate the role and mechanism of sirtuin 1 （SIRT1）??-mediated deacetylation of high mobility group box 1 （HMGB1） in chronic rhinosinusitis with nasal polyps （CRSwNP）. CRSwNP cellular model was established using lipopolysaccharide （LPS）?-induced human primary nasal epithelial cells （HNEpC）. The effects of LPS on cell viability， expression of CRSwNP-related proteins （NLRP3， Caspase-1， TSLP）， SIRT1 expression， acetylation level and translocation of HMGB1， mRNA levels of inflammatory cytokines， and pyroptosis were examined. Furthermore， SIRT1 overexpression model was constructed or cells were treated with exogenous lactate to investigate the roles of SIRT1 and lactate in LPS-mediated pyroptosis. Compared with the control group， 30 μg·mL^-1 LPS had no effect on the viability of HNEpC cells but significantly increased the protein expression of NLRP3， Caspase-1， and TSLP， as well as the mRNA levels of inflammatory cytokines. Simultaneously， LPS significantly downregulated SIRT1 expression， increased HMGB1 acetylation and translocation， induced pyroptosis， and lactate production. Compared with the LPS-treated group， the SIRT1 overexpression group exhibited decreased HMGB1 acetylation and translocation， reduced release of inflammatory cytokines， inhibited pyroptosis， and significantly decreased lactate content in the supernatant. Exogenous lactate significantly downregulated SIRT1 protein expression， promoted HMGB1 acetylation and translocation， and enhanced the release of inflammatory cytokines and lactate. In summary， SIRT1 attenuates LPS-induced acetylation and translocation of HMGB1 in HNEpC， thereby ameliorating pyroptosis and reducing cellular inflammation.

Breast cancer， as the most prevalent malignancy among women globally， exhibits significant prognostic heterogeneity. Transcriptomic data from breast cancer patients in the cancer genome atlas （TCGA） database were analyzed through differential expression and correlation analyses to identify nicotine metabolism-related differentially expressed genes. A prognostic model was constructed using univariate Cox regression and Lasso-Cox regression analyses， and its performance was evaluated using Kaplan-Meier survival curves， ROC curves， calibration curves， and clinical factor-integrated nomograms. The GSE42568 dataset from the gene expression omnibus （GEO） was employed as an external validation cohort for model verification， and further condueted immune infiltration and drug sensitivity assessments. The results showed that the model was composed of 10 nicotine metabolism-related genes， which could be validated as an independent prognostic factor for breast cancer. Immune infiltration and drug sensitivity analyses revealed significant differences in immune cell infiltration and drug responsiveness between high- and low-risk groups. This risk prognostic model can independently predict breast cancer outcomes and provide novel molecular markers and potential therapeutic targets for prognostic evaluation and personalized treatment of breast cancer.

To investigate the changes of active components in Lycium chinense Miller leaf drink fermented by Aspergillus cristatum and its effect on antioxidant activity in vitro， L. chinense Miller leaves（GY） from three distinct production regions in Zhangzhou， Fujian （FZ）， Qingyuan， Guangdong （GQ）， and Nantong， Jiangsu （JN） were harvested. According to the black tea process，L. chinense Miller leaves were withered， rolled and naturally fermented to make L. chinense Miller leaf black tea（GC）. The black tea was fermented by A. cristatum for 2 days to obtain Fermented L. chinense Miller leaf black tea （GCF）. Compared with GY， GCF could improve the taste of L. chinense Miller leaves and remove the grassy flavor； the color of tea soup deepened from orange yellow to orange red； there was no significant change in the content of polyphenols and carotenoids. The content of flavonoids decreased significantly， and the content of flavonoids in JNGCF decreased by 43.44%. Compared with each group of GY， the contents of protein， total polysaccharides and total free amino acids in FZGCF， GQGCF and JNGCF were significantly increased. The protein increased by 50.70%， 49.07% and 55.34%， respectively； the total polysaccharide increased by 98.93%， 113.15% and 100.42%； the total free amino acids increased by 75.90%， 82.38% and 68.84%. In the in vitro antioxidant activity test， the DPPH free radical scavenging rate of FZGCF was significantly reduced， while there was no significant difference between GQGCF， JNGCF and their respective GY groups， and the reducing power of FZGCF， GQGCF and JNGCF was significantly reduced. The results showed that GCF groups could improve the taste， increase the redness of tea soup， preserve the original antioxidant active substances polyphenols and carotenoids to a large extent， and increase the nutritional substances protein， polysaccharides， and amino acids. The above results provide a theoretical basis for the development of functional products of L. chinense Miller leaf， filling the gap in L. chinense Miller leaf black tea products and reducing the resource waste rate of L. chinense Miller leaf.

To investigate the regulatory effects of chitooligosaccharides （COS） on physiological characteristics of Brassica pekinensis seedlings under salt stress， the cultivar "Cold-tolerant Golden Empress" was used. Seedlings were foliar sprayed with 0 （CK）， 50， 100， 150， or 200 mg·L^-1 COS for 4 days and then subjected to salt stress with 150 mmol·L^-1 NaCl. The results showed that the 100 mg·L^-1 COS treatment significantly increased plant height and dry weight per plant under NaCl stress， increasing by 14.44% and 88.06%， respectively. It also significantly enhanced the activities of antioxidant enzymes peroxidase （POD） and catalase （CAT） by 16.41% and 33.77%， respectively， while significantly reducing malondialdehyde （MDA） content. Furthermore， the net photosynthetic rate （Pn）， transpiration rate （Tr）， and stomatal conductance （Gs） of the leaves were significantly increased by 28.26%， 41.67%， and 15.90%， respectively， whereas intercellular CO₂ concentration （Ci） was significantly reduced. Proline content also increased significantly. These results indicated that 100 mg·L^-1 COS effectively alleviates salt stress-induced damage in Brassica pekinensis seedlings by enhancing antioxidant defense and photosynthetic efficiency， providing a theoretical basis and technical support for stress-resistant cultivation of highland summer vegetables.

Cyclosporin A （CsA） is a secondary metabolite with multiple biological activities such as immunosuppression， antibacterial， and anti-inflammatory effects， which holds significant application value in clinical treatment and the biomedical field. To further increase the fermentation content of CsA， based on single-factor experiments， the optimal fermentation conditions were obtained through Plackett-Burman design， central composite design （CCD） and response surface analysis （RSM）. The results indicated that the contents of corn steep powder， ammonium sulfate， glucose， and the fermentation time had a significant impact on the biosynthesis of CsA. Eventually， the suitable medium composition was determined as follows： 8.0% maltodextrin， 6.88% corn steep powder， 0.15% yeast extract powder， 0.18% ammonium sulfate， 0.61% glucose， and 0.1% PEG200. The optimized fermentation parameters were a cultivation temperature of 24 ℃ and a fermentation time of 10.8 days. The fermentation yield of CsA reached 11.76 mg·mL^-1， which was increased by 47.95% compared with the initial conditions， after the optimization of the fermentation process. The research results provide important theoretical basis and technical parameters for the process scale-up of this strain.